Field of Invention
The present invention relates to a magnesium alloy, and particularly to a quasicrystal and alumina mixture particles reinforced magnesium matrix composite; the present invention also relates to a method for manufacturing the quasicrystal and alumina mixture particles reinforced magnesium matrix composite.
Background of the Invention
Since magnesium alloys have the advantages of low density, good vibration damping behavior, easy processing, good electromagnetic shielding and the like, they are widely used in the fields of aerospace, automotive transportation, digital products and the like; wherein, Mg—Al—Zn magnesium alloys become a hot spot in research and application field of the magnesium alloys due to their excellent mechanical property, good fluidity, low thermal cracking tendency, relatively simple casting process and low cost. However, Mg—Al—Zn magnesium alloys are easily oxidized to burn during smelting and inherit the disadvantages of low tensile strength and low elongation of traditional magnesium alloys, so that further application of the magnesium alloys is hindered in structural materials. Thus, a method for preparing magnesium matrix composites by adding a reinforcement phase is usually adopted to improve the properties of the magnesium alloys.
Currently, research for a non-continuous reinforced magnesium matrix composite is mainly active internationally, and a reinforcement phase of the non-continuous reinforced magnesium matrix composite mainly is silicon carbide (SiC) particles, boron carbide (B4C) particles, silicon carbide (SiC) whiskers, carbon nanotubes, and so on. And particularly, particles-reinforced magnesium matrix composites become one of development direction of composite materials at present because of the advantages of simple manufacturing process, low cost, workability, isotropy and the like. In addition, an interface is an important characteristic of the composite materials, interface reaction and interface formation play a decisive role for the properties of the composite materials. In the process of manufacturing the composite materials, the reinforcement phase of matrix is likely to react and form a new compound at the interface. However, for a common method for reinforcing the magnesium matrix composites by only adding ceramic particles, there are the problems of poor wettability between the particles and the matrix, poor interface reaction, outdated preparation process and high production cost, which largely restrict improvement of the comprehensive properties of the magnesium matrix composites and limit their wider application.
Currently, there are the following main methods for preparing the particles reinforced magnesium matrix composites: 1. a hot-pressing method in which pressing is conducted in a heating state so as to increase density of microscopic structure of the materials, thereby achieving a reinforcement purpose; 2. a hot-rolling method which only applies to processing of section bars and bars generally and does not apply to preparation of magnesium-based alloy parts having complex shapes and high performance; 3. a stirring-casting method in which a conventional casting method is adopted and reinforcement particles are added into a liquid or semi-solid melt so as to obtain a magnesium matrix composite, since solidification and crystallization perform under gravity, pores, cracks, shrinkage porosities and other defects easily occur, these factors result in that it is difficult to achieve the expected reinforcement effect. 4. a powder metallurgy method in which a particles reinforcement phase and a magnesium alloy matrix powder are squeezed or sintered using a powder metallurgy technique at high temperature to form a composite material—method has relatively high cost and is not conducive to industrializing production.